I don't think it was a conscious thing, forgetting to give Bella a strength and a clear victory of her own at the end. (Well, she does have an impenetrable mind, but I never got a clear sense of the why of that--maybe in another book.) I know that when I started writing my now-in-revision-stage first novel, my male lead kept doing interesting things, and suddenly he had this whole backstory, and things to overcome--whereas my actual MC (first person girl) was just kind of living through a series of odd events, recording what she saw happening to the guy. Basically, he started taking over, and I had to really scale back, and consciously assign a clear (and dominant) character arc for my MC. (Now, unfortunately, readers are telling me that the guy needs to overcome more at the end--ah, well, back to the drawing board.) I wonder if that's the kind of thing going on here. I really liked Edward's character arc--the idea that we always have a choice, no matter what our circumstances (ie, even if you're a vampire). The whole time he's fighting to be morally human, and finally proves himself when he's able to save Bella's life and not give in to snackies. That was very satisfying to me.
But wait, you say! Bella is the main character here! Right. Maybe I'm totally misreading things, but I felt like Meyer *wanted* us to feel Bella was making bad decisions. Her desire to just have someone bite her was pretty self-destructive, and it wasn't very considerate of others, either (what if she ate her family and friends?). She's got some growing to do. I hope she gets her head together over the series. (And at the same time, I want a happy ending...)